1. Field of the Invention
The present invention relates generally to direct dispensing systems for liquid, agriculturally based chemicals; and, more particularly, to agriculture chemical dispensing systems for nozzle-less, uniform, direct delivery of liquid agriculture chemicals to the soil.
2. Description of Related Art
Agriculture is a multi-billion dollar business in the United States and throughout the world. Especially in the United States, agricultural techniques and science have advanced dramatically. Increased yield and decreased labor, with earlier maturity, and hardier plants, have led to a new efficiency and productivity in farming. For example, hybrid seeds are produced, which are matched to specific soils, climates, and the like, as well as being resistant to certain pests, bacteria and fungi.
Fertilizers, herbicides, fungicides, additives, enhancers and other agrichemicals have been refined to the point that they increase yield dramatically, even in the absence of ideal soils and growing conditions. For example, chemigation is used to apply fertilizers and other agrichemical products through an irrigation system. This procedure involves the introduction of agriculturally based chemicals into irrigation water to provide for intimate admixing of the chemicals and the irrigation water stream, such that the subsequent dispersion of the irrigation water carries, well admixed therein, the agrichemicals onto the cropland. Chemical products, such as fertilizers, insecticide, pesticides, herbicides, fungicides, etc., can be dispensed by this method. Such chemicals, however, need be well dispersed in the irrigation water prior to the water being sprayed upon the cropland. This technology has reached a point where agrichemicals, even those that are hydrophobic, can be uniformly disbursed in the aqueous flow of the irrigation method. Much time and effort has been devoted to uniformly delivering such agrichemicals by these means.
However, as effective as chemigation is, there are certain draw-backs to this method of delivering or disbursing agrichemicals to a crop. One draw-back is that the agrichemicals can only be delivered to the crop during watering. Another is that this broadcast type distribution is not “site specific” for the particular application, thus, resulting in application of a greater amount of agrichemicals than needed, increasing costs.
In an attempt to mitigate these problems, other agrichemical dispensing systems have evolved for application of agrichemicals directly to or even beneath the soil proximate the seed or plant sometimes in combination with other farming operations such as tilling. Crop dusting from an airplane is one method, but has obvious drawbacks, especially for highly toxic materials. Additionally, this aerial spray method is not effective in transferring agrichemicals directly to the soil. Another delivery system involves use of spray nozzles, which are positively fed by pressurization and are moved over the terrain to be treated by means of mobile implements or trailers. These systems, usually pulled behind a tractor, position a nozzle proximate the ground to be treated. Although useful for some topical applications, these systems also have draw-backs. First, the spraying from a nozzle results in airborne particles or mist, which is not only wasteful, but can result in contamination of other crops, animals, inhabitants, and the like including the tractor operator. Additionally, the application is topical, which does not always bring the agrichemical in contact with the seed, plant, or the like, i.e. nozzles are usually used in a soil surface application. Further, nozzle systems are not precise, spraying material over a wider area than necessary for the specific application; and, finally, nozzles tend to clog.
One way of overcoming the draw-backs of using a surface application nozzle is to directly deposit the liquid additive or agrichemical into a furrow, slit, or other indentation or cut in the soil, preferably during some agricultural operation such as tilling, planting, weeding(cultivating), or the like. In accordance with this method, hoses or tubes connected to a reservoir of the agrichemical to be applied are placed proximate, but behind the tine, disk, or row planter to deposit a measured amount of chemical such as fertilizer, insecticide, herbicide, or the like beneath the soil proximate the seed, the plant root and/or the tilled soil.
Many devices have been suggested for regulating and/or controlling the amount of chemical delivered to the tip of each delivery tube to assure uniform distribution across the entire width of the implement toolbar. One problem in delivering a uniform amount of agrichemical containing liquid to the dispersing end of the delivery tube is the lack of any type of restraining device to provide a back pressure at the end of the delivery tube. That is, the tube end is open. For example, with nozzle delivery systems, the nozzle presents the resistance to flow, which creates a back pressure in the system, kind of like a sprinkler system, which equalizes the flow through each of the unobstructed nozzles within the network.
Since direct distribution or open tube systems do not employ such a back pressure device, the material must be uniformly divided into the delivery tube prior to its expulsion onto the particular application proximate the agricultural target. In addition, the delivery tube sizing is important in restricting fluid flow against the pressure of the system through the distribution manifold. Many mechanized and electric flow meters have been proposed to individually regulate the amount of material passing into, and thus, out of the delivery tubes. These systems, in addition to being expensive, are complicated to regulate.
Mechanized agriculture, although efficient, puts substantial operational environment stress on mechanical devices. Farming, including tilling, planting, and cultivating, all involve equipment operation in the presence of a substantial amount of dirt, sand, grit, and the like. Therefore, complicated devices, which involve electromechanical valves, valve seats, and the like, require a high degree of maintenance for efficient operation. Agrichemical dispensing systems, which usually are carried on a toolbar behind, for example, a tractor, are subject to large amounts of this dust, dirt, and the like. Therefore, it would be advantageous to have a simple system that does not employ individual valves, flow meters, and the like, to uniformly dispense aliquots or drops of the liquid material proximate the work area in the soil.
Unfortunately, passive dividers, splitters, and manifolds of the prior art do not provide the consistency of the liquid agrichemical liquid stream splitting or dividing to assure uniform distribution of the feeder stream to the individual delivery tubes. For example, the prior art splitter or divider shown in FIG. 1, merely branches a single feeder stream into three branches. Thus, as can be seen from the FIG. 1, the center branch has less resistance than the two side branches and, thus, without further regulation will carry more agrichemical than the side branches. Likewise, as shown in FIG. 2, a prior art linear manifolds involve a series of nipples or connection at right-angle to the fluid flow, which allow the linear flow of material to exit along the vertical access of the manifold through the connectors. Again, as can be seen, the flow rates through all of the connections will not be uniform from this device.
In today's “super” mechanized farm implement era, planters, tillers, cultivators, and the like are pulled behind large tandem-tired tractors of substantial power. This allows use of large toolbars, which cover broad areas of the field. In modern agricultural setting, agricultural toolbars spanning fifty to a hundred feet are not uncommon. When direct application or open delivery tube systems are utilized, these large toolbars require an extensive network of fluid dividers and conduits connecting the reservoir to the delivery tube. Delivering a uniform amount of agrichemical material to each workpiece along these long toolbars, therefore, becomes a substantial challenge. These complex delivery networks make it difficult, if not impossible to deliver a uniform aliquot of agrichemical to each individual delivery tube for application. Clogging of a gang of delivery apparatus or even a single apparatus can detrimentally affect the crop yield.
It would be, therefore, advantageous to have a simple, reliable system for uniformly disbursing agrichemicals by dripping such agri-chemicals from the exit end of the delivery tube proximate the working surface of a tilling, planting, or furrowing implement, which is highly adjustable. It would further be desirable to have such a system, which could employ numerous branches in series, yet delivers uniformly the liquid material to be disbursed at the exit end of each delivery tube without complicated valves, flow meters, or the like.